高重频激光控制IV型激波干扰方法研究

Flow Control Method of Type IV Interaction with High Rated Laser Energy

关键词:  高重频  激光能量  准静态波  激波干扰  流动控制

Key words:  High rated  Laser energy  Quasi-steady wave  Shock interaction  Flow control

摘要:

在实验和数值分析IV型激波干扰特性及其对飞行器表面压力和热流影响的基础上，提出采用脉冲激光能量控制IV型激波干扰的方法，以降低飞行器波阻、驻点压力和热流。采用实验和数值方法，研究了100mJ单脉冲激光能量与马赫5.0条件下IV型激波干扰的相互作用过程，揭示了单脉冲激光能量控制IV型激波干扰的机理。数值研究了频率为150kHz的激光能量注入后，激光空气锥的形成及其与IV型激波干扰的相互作用过程，得到了钝头体表面压力、热流和波阻的演化过程。结果表明，沉积高重频的激光沉积方式可以利用相对较少的激光能量形成比较稳定的准静态波结构，进而利用准静态波与IV型激波干扰的相互作用将高能区脱离钝头体表面。在马赫数为5.0的流场中沉积频率为150kHz、单脉冲能量为5mJ的激光能量可使峰值压力、热流和波阻分别降低40%，33%和23%。

Abstract:

The effects of type IV shock interaction on surface pressure and heat flux of the blunt body were analyzed through calculation and experiment. In order to decrease the wave drag，peak pressure and heat flux，the flow control method of type IV shock wave interaction by laser energy deposition was proposed. Single pulsed laser energy with 100mJ was deposited in Mach 5.0 flow with both experimental and calculation. Mechanisms of flow control of type IV shock interaction with single pulsed laser energy were disclosed. High rated laser energy with 150kHz was deposited to form the quasi-steady wave structure by simulation. Processing of the distribution of surface pressure，heat flux and wave drag during the interaction were obtained. The results show that quasi-steady wave structure could be formed with less laser energy under the condition of high rated laser energy. The high energy area could be detached from the blunt body surface during the interaction of quasi-steady wave and type IV shock wave structure. With the laser energy frequency of 150kHz，single shot with 5mJ deposited in Mach 5.0 flow，the peak pressure，heat flux and wave drag could be decreased by 40%，33% and 23%，respectively.